Flow control device for a ventilator hood

ABSTRACT

In a common casing, a domestic appliance comprises an oven ( 60 ) and a ventilator device ( 20 ). The ventilator device ( 20 ) has a ventilating duct ( 21 ) extending between at least one inlet opening ( 23 ) and at least one outlet opening ( 24, 25 ) on the outside of the casing ( 50 ). A ventilator ( 22 ) arranged in the ventilating duct ( 21 ) is stationarily mounted in the casing ( 50 ) spaced from the outlet opening ( 24, 25 ). A flow control means ( 30 ) is arranged in the casing ( 50 ) downstream of the ventilator ( 22 ) for adjusting the duct ( 21 ) to lead out at any one of at least two outlet locations ( 16, 17, 18 ). A suitable flow control means ( 30 ) has an elongated control means housing ( 39 ) and comprises an outlet opening ( 32 ) and an inlet opening ( 31 ). The outlet opening ( 32 ) is arranged along a long side and the inlet ( 31 ) opening is arranged along another side and has a smaller opening area than the outlet opening ( 32 ). A deflecting device ( 40 ) is arranged in the flow control means ( 30 ) for deflecting and distributing the flow essentially uniformly at the outlet opening ( 32 ).

TECHNICAL FIELD

The present invention relates to a domestic appliance comprising an ovenand a ventilator device in a common casing according to the preamble ofthe appended claim 1 and a flow control means and the use thereof insuch an appliance.

PRIOR ART

Domestic appliances which in a common unit comprise a microwave oven anda ventilator hood are previously known. Such combinations of aventilator hood and a microwave oven are intended to be installed over arange and offer efficient utilisation of the space above a range.

Usually, the ventilating duct in such domestic appliances has an outletwhich at the time of installation is adjustable to suit various designsand placements of subsequent kitchen flues in a building. Often, as analternative, the outlet of the ventilating duct can guide the flow inthe duct to recirculation, e.g. when the building lacks a suitablekitchen flue, so that the ventilator hood can function as arecirculation ventilator, together with a suitable filter.

These known domestic appliances have a ventilator unit arranged directlyopposite an outlet opening. Usually, the outlet opening is formed as arectangular opening in the transition area between the top and back ofthe appliance. In this connection, the ventilator unit is formed as aradial ventilator with twin rotors, which are arranged on each side of acentrally located electric motor. The ventilator has a horizontalrotation axis extending in the transverse direction of the appliance.The diameter of the rotors essentially corresponds to the dimension ofthe outlet opening in the direction upwards-downwards orforwards-backwards. The ventilator unit forms a rectangularparallelepiped and can be placed in different turning positions aroundits rotation axis for adjustability between outlet upwards or backwardsto a ventilating duct in the building or for outlet forward through asecond outlet opening on the front of the appliance for recirculation.

One problem associated with this known construction is that theventilator and the air currents give rise to high sound levels.

Furthermore, there are special problems associated with ventilatordevices which are combined with an oven, such as combining a number ofappliance components and ventilating ducts in a limited volume in acommon casing. Therefore, there are problems of low ventilatorefficiency because of uncontrolled flow in the appliance. In knownappliances, a high percentage of the air which is blown out through theventilator leaks into the outer casing of the appliance from a differentlocation than the intended inlet opening.

SUMMARY OF THE INVENTION

The object of the present invention is to achieve an improved ventilatordevice in a domestic appliance comprising an oven and a ventilatordevice in a common casing.

In this connection, special objects are to lower the sound level of theventilator device and to achieve improved controllability of aircurrents in the appliance.

These and other objects, which can be seen from the description below,have now been achieved by the invention by means of a domestic applianceand a flow control means, which are of the kind described in theintroduction and which in addition have the features stated in thecharacterising clauses of claims 1 and 9, and by a use of the flowcontrol means according to claim 16.

Thus, in the domestic appliance according to the invention, theventilator is stationarily mounted on the inside of the casing, spacedfrom an outlet opening.

In addition, the ventilating duct has a flow control means arrangeddownstream of the ventilator on the inside of the casing for adjustingthe ventilating duct to lead to any one of at least two different outletlocations.

In this way, it becomes possible to choose the location and the designof the ventilator inside the casing or cover of the appliance. Forexample, the ventilator can be given a larger radius or be locatedcloser to the intake opening of the appliance. Greater possibilities areafforded for the design of a suitable ventilating duct in coactionbetween the ventilator and the other components of the appliance. Inaddition, it becomes possible to utilise a larger part of the area ofthe outlet opening for the outlet air, which means that an equally largevolume flow rate can be ventilated at lower outlet velocities. This, inturn, leads to lower sound levels than have been possible in knownappliances, in which ventilator constructions only allow a smaller partof the outlet opening to be utilised.

In a preferred embodiment the flow control means is adapted to changethe direction of a flow in the ventilating duct. As a result, theadjustability of the flow control means and the optional location of theventilator can be achieved in a simple way by the fact that the flowcontrol means can be placed in various turning positions around anintake from the ventilator.

In a particularly preferred embodiment, the flow control means has acontrol means housing with a smaller inlet and a larger outlet in orderto function as a diffuser. In this way, the velocity of flow in theoutlet can be lowered, which leads to lower sound levels. At the sametime, the ventilating duct can be given a limited cross-sectional areabetween the ventilator and the flow control means.

It is a preferred feature that the ventilator be given a relativelylarge radius, larger than the smallest dimension of the outlet opening,something which has been the case in the known solutions. By virtue of alarger radius, the peripheral speed of the ventilator can be reduced inrelation to the flow rate, which leads to lower rotation speeds and thuslower sound levels. It is a particularly preferred feature that theventilator be arranged in the form of a radial ventilator which rotatesaround an asymmetrically located, vertical rotation axis in an upperarea of the appliance. In this way, the radius of the ventilator willonly be limited by the horizontal cross-sectional dimensions of theappliance.

A flow control means according to the invention has an elongated controlmeans housing and comprises an outlet opening, which is arranged along along side, and an inlet opening, which is arranged along another side.The inlet opening has a smaller opening area than the outlet opening. Inaddition, a deflecting device is arranged to deflect and distribute theflow essentially uniformly at the outlet.

Such a flow control means has proved to be extremely suitable forcontrolling a flow to an outlet opening in a domestic appliance with aventilator in combination with an oven. The flow control means accordingto the invention also affords great advantages in appliances which havea fixed outlet location.

In a preferred embodiment, the deflecting device comprises a pluralityof deflecting means, which are essentially uniformly arranged along aprojection of the inlet opening perpendicular to its essentialgeometrical plane and at the same time essentially uniformly arrangedalong a projection of the outlet opening perpendicular to its essentialgeometrical plane. In this way, deflection of the air current as well asa reduction of velocity and a uniform distribution of the same over thelarger area of the outlet are achieved with a small loss of energy.

The deflecting means of the flow control means preferably comprisesdeflecting blades which are somewhat curved and have a leading edgefacing the inlet opening and a trailing edge facing the outlet opening.In order to achieve good flow characteristics and little energy loss, itis particularly preferred that the leading edge of the blades be roundedand that the trailing edge be pointed.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be described in more detail below with reference tothe accompanying drawings, which show presently preferred embodiments ofthe invention.

FIG. 1 shows a domestic appliance according to the invention in aperspective view obliquely from the front from above.

FIG. 2 shows the domestic appliance according to FIG. 1 in a perspectiveview obliquely from behind from below.

FIG. 3 shows the domestic appliance according to FIG. 1 with certainparts removed in order to illustrate the function of the appliance.

FIG. 4 is a schematic longitudinal section along the line IV—IV in FIG.3 for illustrating the flow of air through the appliance.

FIG. 5 is a schematic cross-section along the line V—V in FIG. 3 forillustrating the flow of air out from the appliance.

FIG. 6 is a perspective view of a flow control means according to theinvention.

FIG. 7 shows the flow control means in FIG. 6 in a disassembled state.

DESCRIPTION OF PRESENTLY PREFERRED EMBODIMENTS OF THE INVENTION

FIGS. 1 and 2 show a domestic appliance 10 which in one unit is acombination of a microwave oven and a ventilator hood (Over-the-range)to be located above a range. The appliance 10 comprises a casing 50which has the form of a rectangular parallelepiped. On the front 53 ofthe casing 50 there is a door 61 for the microwave oven 60 and a controlpanel 62. On the underside 51 of the casing 50 there is an inlet opening23 with a grate for the ventilator hood and on the back 54 and the topside 52 there is an outlet opening 24 extending along the intermediateedge 55, which opening is intended to be connected to a building kitchenflue located above or behind it, adjacent to an upper or a rear outletlocation 24 a or 24 b respectively. In the embodiment shown, the shapeof the outlet opening is specially adapted to a kitchen flue with arectangular cross-section. On the front 53, there is also a secondoutlet opening 25, which is provided with a grate and intended forrecirculation of air if the ventilator hood is used as a recirculatingventilator, e.g. when the building lacks suitable ventilating ducts. Aventilating duct extends in the casing 50 between the inlet opening 23and the outlet openings 24 and 25. It can be seen from FIG. 5 that theair current is adjustable between three different outlet locations 24 b,24 a, 25, each of which corresponds to a respective outlet route 16, 17,18 for adjustment to the existence and location of kitchen flues in thebuilding. The features described so far correspond to the features of aconventional type device.

In FIG. 3, the appliance 10 is shown with certain parts cut away, whichmakes it possible to see an adjustable flow control means 30, which willbe described in more detail below, and a radial ventilator 22, which isspaced from the outlet opening 24. Around the ventilator 22, there is aventilator casing duct 26 which collects and guides the air current onthe driving side of the ventilator to the flow control means 30. Theseparts form part of the ventilating duct 21 of the appliance 10. The flowcontrol means 30, which is elongated is, e.g. in connection with theinstallation of the appliance, adjustable in the turning position aroundits longitudinal axis for adjustment of the outlet location and outletroute of the ventilating duct 21 according to FIG. 5.

The ventilator 22, the ventilator casing duct 26, the flow control means30 and a recirculation duct 27, which extends between the flow controlmeans 30 and the recirculation outlet 25, are all arranged in an upperplane 57 directly below the top side 52 of the casing 50. As can be mostclearly seen in FIG. 4, this upper plane 57 is arranged above and spacedfrom the oven 60 in order to permit the supply of air between them. Theventilating duct 21 consists of the free volume in the casing 10 whichis not taken up by the oven 60 and by drive components 63 for the ovenand the ventilator. As can be seen in FIG. 4, the ventilating duct 21with two sub-ducts 21 a and 21 b extends from the inlet opening 23 onone side around the oven 60 and on the other side around the drivecomponents 63 of the appliance.

The location and design of the ventilator 22 shown in FIG. 3 offers manyadvantages. For example, it has been possible to give the ventilator 22a large diameter, here in the range of ⅓ to ½ of the depth of the topside 52. Further, the asymmetric location of the ventilator 22 allowsthe motor to be located in the space beside the oven 60. The location ofthe ventilator 22 relatively close to the outlet opening permits theachievement of an even, directed flow in the ventilator casing duct 26while the ventilating duct 21 can be made short on the driving side,i.e. the part which has to be particularly carefully sealed.

In addition, the risk of leakage of currents into the casing adjacent tothe outlet opening 24, which has been a problem in known constructions,is reduced by the ventilator and in particular its intake being locatedspaced from it.

The embodiment shown with an elongated flow control means 30 in theoutlet opening 24 is very well suited to be connected to kitchen flueswith a rectangular cross-section. A major advantage in this connectionis that a perpendicular and uniformly distributed flow is achieved overthe whole area of the outlet opening, which leads to a small loss ofenergy and low sound levels.

The flow control means 30 according to the invention is described inmore detail below with reference to FIGS. 6 and 7. The ventilationcontrol means 30 has two simultaneous functions, one being to functionas a diffuser, and the other being to change the direction of the flow.By the ventilation control means 30 according to the invention, boththese tasks are accomplished while, at the same time, a uniform flow ismaintained along the outlet area of the ventilation control means 30.

The ventilation control means 30 has a control means housing 39 which isshaped like a rectangular parallelepiped with an inlet opening 31, whichconsists of a square short side. Furthermore, there is an outlet opening32, which consists of a whole long side. The flow into and out of theflow control means 30 is indicated by flow arrows 36, 37. A deflectingdevice 40 comprising deflecting means in the form of deflecting blades47 for deflecting the flow uniformly along a line extending diagonallyin relation to the inlet as well as the outlet direction 36 and 37,respectively, extends in the ventilation control means 30.

FIG. 7 shows the flow control means 30 in a disassembled state, whichmeans consists of an elongated cover 35 with a U-shaped cross-sectionand open short ends, as well as a deflecting unit 45, which in one pieceincorporates deflecting blades 47, a holder device 43 for the deflectingblades 47 and a short side wall 46. The housing 39 of the control meansis formed by the cover 35 and the short side wall 46.

The cover 35 is preferably made of plastic and has holder openings 34for coaction with corresponding holder pins 44 on the deflecting unit 45in the assembled state. Guide bars 38 are arranged on the inside of thecover 35 along the central long side 33 to guide the surface flow.

The deflecting unit 45, too, is preferably integrally formed in plasticand has a set of deflecting blades 47 uniformly located along a straightline. The holder device 43 consists of an essentially triangular flatplate extending perpendicular to the deflecting blades 47, parallel tothe direction of flow. The holder device 43 is connected to the shortside wall 46, perpendicular to the same.

The blades 47 are elongated transversely of and bent along the directionof flow and have a leading edge 41, which is rounded and when assembledfaces the inlet opening 31, and a trailing edge 42, which is pointed andwhen assembled faces the outlet opening 32.

The holder pins 44 are formed on the ends of the blades 47 and on theshort-side wall 46.

On the end which is turned away from the outlet opening 32, theshort-side wall has a bent portion 48 for the smooth deflection of theflow along the inside surface of the flow control means 30.

The dividing of the flow control means into a cover and a deflectingunit allows for expedient and efficient manufacturing and assembly.

What is claimed is:
 1. A domestic appliance comprising an oven (60) anda ventilator device (20), which are arranged in a casing (50), theventilator device (20) comprising at least one inlet opening (23) and aplurality of outlet openings (24, 25) on the outside of the casing (50),a ventilating duct (21) extending between the inlet opening (23) and theplurality of outlet openings (24, 25), and a ventilator (22) arranged inthe ventilating duct (21), the ventilating duct (21) being adjustablefor leading out of the casing at any one of the plurality of outletopenings (24 a, 24 b, 25), characterised in that the ventilator (22) isstationarily mounted in the casing (50) spaced from the plurality ofoutlet opening (24, 25), and the ventilating duct comprises a flowcontrol means (30), which is arranged on the inside of the casingdownstream of the ventilator (22) for adjustment between the pluralityof outlet openings (24 a, 24 b, 25), the flow control means (30)includes an elongated control means housing (39) having a long side anda short side, the housing (39) is provided with an inlet (31) along theshort side and an outlet (32) along the long side such that the outlet(32) having a larger area than the inlet (31), a deflecting device (40)is positioned within the control means housing (39) and is adapted todeflect and distribute essentially uniformly a flow from the inlet (31)to the outlet (32).
 2. A domestic appliance according to claim 1,wherein the diameter of the ventilator (22) exceeds the smallestdimension of the outlet opening (24, 25) of the ventilating duct (21).3. A domestic appliance according to claim 1, wherein the casing (50)essentially has the shape of a rectangular parallelepiped with anunderside (51) and a top side (52), the inlet opening (24, 25) beingarranged on the underside (51) and the outlet opening (24, 25) beingarranged in an upper area of the casing (50) and the ventilator being aradial ventilator (22) which is adapted to rotate around a vertical axis(A) in the upper area of the casing (50).
 4. A domestic applianceaccording to claim 3, wherein the outlet opening (24, 25) is centrallyarranged in an upper portion of the casing (50), the ventilator (22)being asymmetrically arranged in relation thereto.
 5. A domesticappliance according to claim 1, wherein the flow control means (30) isarranged along the outlet opening (24) of the ventilating duct (21). 6.A domestic appliance comprising an oven and a ventilator device, whichare arranged in a casing, the ventilator device (20) comprising: atleast one inlet opening and a plurality of outlet openings on theoutside of the casing, a ventilating duct extending between the inletopening and the plurality of outlet openings, a ventilator arranged inthe ventilating duct, the ventilator being stationarily mounted in theventilating duct spaced from the plurality of outlet openings, a flowcontrol housing forming part of the ventilating duct, the housing beingarranged on the inside of the casing downstream of the ventilator foradjustment between the plurality of outlet openings, wherein the flowcontrol housing is elongated and has a long side and a short side, thehousing is provided with a housing inlet along the short side and ahousing outlet along the long side such that the housing outlet has alarger area than the housing inlet, a deflecting device is supportedwithin the housing and forms part of the flow control housing, thedeflecting device is adapted to deflect and distribute essentiallyuniformly a flow from the housing inlet to the housing outlet.
 7. Adomestic appliance according to claim 6, wherein the deflecting devicecomprises a plurality of deflecting blades which are uniformly arrangedwithin the flow control housing, the deflecting blades are curved andhave a leading edge facing the inlet opening and a trailing edge facingthe outlet opening.
 8. A domestic appliance according to claim 7,wherein the leading edge of the blades is rounded and the trailing edgeis pointed.